How to build a random number generator for the blockchain

Blockchain technology's reliance on determinism creates challenges for generating random numbers, which are crucial for applications like games and NFTs. The transparency and consensus of blockchain make it difficult to produce unpredictable random numbers, essential for ensuring fair outcomes. The commit/reveal protocol offers a solution by allowing participants to generate a mutually agreed random value through cryptographic hashing, without disclosing the number on the blockchain itself. This method is demonstrated through a Solidity contract for a casino betting game, which uses random numbers to determine outcomes. The article also discusses strategies to prevent abuse, such as protecting against non-disclosure and frontrunning, ensuring that both sides have an interest in randomness for fair play. The document highlights how, despite the deterministic nature of blockchains, offloading randomness generation to users provides a viable path forward for implementing random number-dependent applications.